The prime minister of Serbia, Aleksandar Vucic says he was prepared to attend ceremonies to mark the 20th anniversary of the Srebrenica massacre.
Nearly 8,000 Bosniak Muslims were killed by Bosnian Serb soldiers, in the town of Srebrenica, called by the UN an act of genocide.
"As prime minister, I am ready to bow my head to show the stand we take towards the innocent victims of Srebrenica," said Mr Vucic.
He described Srebrenica as "hell", but stopped short of calling it genocide.
But the mayor of Srebrenica, Camil Durakovic said Mr Vucic's statement was a "provocation".
"It would have been better if he had said that he did not want to come, because Serbia still neither recognises what happened in the past, nor the judgements confirming that a genocide took place in Srebrenica," he told the AFP news agency.
Mr Vucic was previously a member of a Serb ultra-nationalist party.